Re: Checksums by default?

Jim,

* Jim Nasby (Jim(dot)Nasby(at)BlueTreble(dot)com) wrote:
> On 1/23/17 6:55 PM, Stephen Frost wrote:
> >* Jim Nasby (Jim(dot)Nasby(at)BlueTreble(dot)com) wrote:
> >>As others have mentioned, right now practically no one enables this,
> >>so we've got zero data on how useful it might actually be.
> >Uhm, Peter G just said that Heroku enables this on all their databases
> >and have yet to see a false-positive report or an issue with having it
> >enabled.
> >
> >That, plus the reports and evidence we've seen in the past couple days,
> >look like a pretty ringing endorsement for having them.
> >
> >I'll ping the RDS crowd and see if they'll tell me what they're doing
> >and what their thoughts are on it.
>
> Oh, I read the thread as "there's no data to support checksums are
> useful",

There's been multiple reports on this thread that corruption does
happen. Sure, it'd be nice if we had a report of it happening with
checksums enabled and where checksums caught it, but I don't see any
basis for an argument that they wouldn't ever catch real-world
bit-flipping corruption.

> IIRC Grant's mentioned in one of his presentations that they enable
> checksums, but getting more explicit info would be good.

Frankly, my recollection is that they wouldn't use PG until it had
page-level checksums, and that they run it on all of their instances,
but I'd like to get confirmation of that, if I can, and also hear if
they've got examples of the checksums we have catching real issues.

Thanks!

Stephen